Recently, microwave radars have come into extensive use for determining the velocity and distance of moving objects or for detecting the presence of objects. Generally, the microwave radar of this type requires a radar detector capable of detecting the specific radar waves emitted from the radar.
There are several types of radar detectors using different modes of reception. Unfortunately, however, all types are vulnerable to interference, particularly from external pulse noise. Moreover, they are incapable of precisely discriminating between regular radar waves and leakage radar waves from nearby radar detectors of the single-conversion type. Thus, there is a fair possibility of extraneous waves being confused with the regular radar waves emitted from the regular radar source.